System and method for common control channels in a communications system

Abstract

A method for operating a communications controller includes selecting a search space configuration out of a set of candidate search space configurations for a user equipment served by the communications controller, wherein the search space configuration specifies one or more search spaces to be monitored out of a set of search spaces, and signaling the selected search space configuration to the user equipment.

What is claimed is: 
     
       1. A method for operating a communications controller, the method comprising:
 receiving, by the communications controller from a user equipment (UE) served by the communications controller, a message indicating a search space monitored by the UE; 
 selecting, by the communications controller, a search space configuration from a set of candidate search space configurations based on the search space monitored by the UE as indicated by the message received from the UE, the selected search space configuration specifying one or more search spaces to be monitored out of a set of search spaces configured in a subframe, the set of search spaces configured in the subframe including a common search space in a control region of the subframe, a UE specific search space in the control region of the subframe, a common search space in a data region of the subframe, and a UE specific search space in the data region of the subframe; 
 signaling, by the communications controller, the selected search space configuration to the UE for the UE to monitor search spaces according to the selected search space configuration; and 
 transmitting, by the communications controller to the UE, control information on resource elements of the one or more search spaces according to the search space configuration that is signaled. 
 
     
     
       2. The method of  claim 1 , wherein at least one search space in the one or more search spaces is located in the data region of the subframe. 
     
     
       3. The method of  claim 1 , wherein the selected search space configuration is signaled in a broadcast message. 
     
     
       4. The method of  claim 1 , wherein the selected search space configuration is signaled in a higher layer message. 
     
     
       5. The method of  claim 4 , wherein the higher layer message comprises a radio resource control message. 
     
     
       6. The method of  claim 1 , wherein an indicator of the selected search space configuration is signaled to the UE. 
     
     
       7. The method of  claim 1 , wherein the search space configuration comprises the common search space in the data region of the subframe, and the UE specific search space in the data region of the subframe. 
     
     
       8. A communications controller comprising:
 a receiver configured to receive, from a user equipment (UE) served by the communications controller, a message indicating a message indicating a search space monitored; 
 a processor configured to select a search space configuration out of a set of candidate search space configurations based on the the search space monitored by the UE as indicated by the message received from the UE, wherein the selected search space configuration specifies one or more search spaces to be monitored out of a set of search spaces configured in a subframe, the set of search spaces configured in the subframe including a common search space in a control region of the subframe, a UE specific search space in the control region of the subframe, a common search space in a data region of the subframe, and a UE specific search space in the data region of the subframe, and to generate a first message in accordance with the selected search space configuration; and 
 a transmitter operatively coupled to the processor, the transmitter configured to transmit the first message to the UE notifying the UE to monitor the one or more search spaces according to the selected search space configuration, and transmit control information on resource elements of the one or more search spaces according to the search space configuration. 
 
     
     
       9. The communications controller of  claim 8 , wherein the transmitter is configured to transmit the first message in a broadcast message. 
     
     
       10. The communications controller of  claim 8 , wherein the transmitter is configured to transmit the first message in a higher layer message. 
     
     
       11. The communications controller of  claim 10 , wherein the higher layer message comprises a radio resource control message. 
     
     
       12. The communications controller of  claim 8 , wherein at least one search space in the one or more search spaces is located in the data region of the subframe.